Dirigible trailer



Oct. 25, 1949. G. D. wlLLET DIRIGIBLE TRAILER 4 Sheets-Sheet 1 Filed Aug. 3, 1946 fr, r lll'..

ATTdPNEYS oct. 25, 1949.

G. D. WlLLET DIMGIBLF TRAILER Filed Aug. 3, 1946 4 Sheets-Sheet 2 IN V EN TOR.

A TTORNEY G. D. WILLET DIRIQIBLETBAILER Oct. 25,- 1949.

4 Sheets-Sheet 3 Filed Aug. 3, 1946 Patented Oct. 25, 1949 #U N1 reo STATES EfflivrENT oil-F1os 11 Claims. 1 'This invention. relates to. dirigible trailers. The drivers of tractor-trailer trains have long fhadtrouble .with failure. of trailers to track properly. :The greatest difculty arises when attemptingto. back up witha tractor-trailer combination. .Unlessthis maneuver is done by an eX pertpf long-,standing experience, the train is almost certain to jack-knife. The difculty is, ofcourse, not limited to jack-knifing while backingnup, but extends also to improper tracking while. moving. in the forward direction.

fIt is thev object of this invention to provide a trailer vwhich mayfbe steered in either direction vof operation, and which is steered automatically by the relative-motion of the towing vehicle and the trailer. 'I'his is accomplished by wheels on the trailer which are steered by means of linkage voperated by themeans coupling the tractor and trailer together.

In the drawings:

Fig. leis a plan View of the chassis of a trailer made according to the invention, with the parts shown in position for forward. motion.

Fig 2 isaview'in section substantially on line 2-2 of Figure 1.

Fig. 3 is a plan view of the trailer shown in Figurel but with the parts shown in their relative positions for backing up the tractor-trailer train.

Fig.- 4 is a plan view of the chassis of another embodiment of the invention.

Fig.'5 is a detail view of the lock member shown inFigureA.

Fig. 6 is a view in section substantially on line 6-6 of Figure 5.

Fig. '7 is a detail plan View of the lock mechanism shown in Figures 1, 2 and 3, with the parts shown in their relative position for forward motion.

Fig.` 8 is a side elevation view showing in detail thelock mechanism of the trailer of Figures 1, 2 and 3, with the parts occupying their relative positions for backing up the train.

Fig. 9 is a View in section on line 9 9 of Figure '7 and Fig. 10 is a View in section on line Ill-I0 of Figure 9.

Referring now in detail .to the drawings, a trailer made according to the invention is shown as havinga frame 2 which consists of side rails 4 and cross members 6, 8 and I0. An axle l2 supports the side vrails 4 through springs I4. Wheels I6 are dirigibly mounted on the axle by means of steering knuckles I8. Steering arms 20 are joined by a suitable actuating memberesuch as itieyrod 22;whichdirigibly moves .the wheels in unison. Steering .arms 20are shown-.as ,being vpointed. outward, insteadrof beingparallel. The ypurpose of this arrangement of the steering-arms `is -toy permit the. insidewheel one-a .curve ,to be turned further than the; outside lwheel,lin..order that the insidewheel mayvdescribe asmallercircle-.without Iscuiiing ythe tires.

A- member V24, which -for convenience lmay be .called a reach, is pivotally mounted .at 26 .oncross member 8 and engages tie rod 22` by-meansoia .pin 28 onthe tiefrod cooperating `withyaslot :.30 in the .endA of the reach. A steering damper-in the, for-m of springs 32h isv` preferably applied near theend of the reach. Springs 32 are joined .-.at one endto the reach and at .the other end .tothe side members..4 lor toiany other suitableportion of .the frame, .and preferably operate. under tension.

A second member,34, whichfor convenience may bev called -a tongue, is pivotally mounted .on crossmember l0. at 36. AA. slot- 38 in the tongue permits limited reciprocable movement of tongue 34 relatively to the frame 2. Tongue 34 carries a. bifurcated hitch member"40-at-itsforward end ,-.wh-ichis'adapted to be secured'to atractor .or

towing vehicle 42.

v.As canv be .seen from Figures 1 and 2,.the reach :24 and tongue 34 overlap to-some extent. Apro- .jection such as.pin.44 is provided on one of the pivotallymounted members (on tongue 34 inthe embodiment shown) in front of onefof the pivot Yaxes (pivot -26 in the embodiment shown) for cooperation with a T-shaped recess in a plate -46 which. isintegral with. the otherpivotally mounted member (reach 24.in the embodiment shown). VAsecond projection in the form of pin 48 is shown on one1 ofthe pivotally-mounted members (reach .24 in-the embodiment shown) behind thepivot 26. Pin 48.c0operates,with.a Tf-shaped slot ina plate .50 which .is integral withthe other pivotally -mounted member (tongue 34 in the embodiment shown). As is best seen in Figure 2 each of plates 46 and- 50 .formsa closed loop .52 and 54respec tively. .Loop52surrounds the tongue 34 and loop 54 surrounds the reach 24. At or near .the for- .Ward .end of frame Zthere is provided lock means which consists of a member 56 secured to -.the frame .2 .and having an-elongated recess 58. The vlongaxis of recess-58 is .showninFigure 1, and the short .axis thereof .is shownin Figure 2. .Cooperating withthe recess `58-.is alock member which `is connected to be actuated from .the drivers seat throughrod, .bell crank 4At4, and rod 66.

The details of lock member 60 are shown in Figures 7 and 10 inclusive. As can be seen from those figuresy the lock member consists of a spindle 68 rotatable in a saddle type bearing 10 and held against longitudinal displacement relatively to the bearing 10 by means of collars 12. A crank arm 14 is provided for rotation of spindle 68. Crank arm 14 is connected to be actuated by rod 62, referred to above. Spindle 68 carries an elongated member 16 which has the same general shape as the elongated recess 58. See especially Figure 10. To the rear of elongated member 16 there is mounted a guide 18 which projects into the recess 58 for normal forward movement of the tractor-trailer train.

Figure 4 shows another embodiment of the invention. In this figure the invention is shown as applied to a semi-trailer. As before, frame 2 is shown having side rails v4 and cross members 6, 8 and I0. In this embodiment, however, frame 2 is carried at its forward end on a fifth wheel 80 of a tractor 8.2, by means of the converging members 84 carrying a bearing plate 86 in which is mounted a pin 88 for cooperation with the fifth wheel in a manner which will be well understood by those skilled in the art.

Axle 90 carries `wheels 92 which are dirigibly mounted on knuckles 94 and are connected to be turned on their vertical axes by means of steering arms 96. Steering arms 96 are connected to be moved in unison by an actuator such as tie rod 98, which is disposed ahead of the axle 60. With tie rod 98 ahead of the axle the ends of steering arms 96 point inward in order to give the inside wheel'a sharper turning angle so that it may describe an arc having a smaller radius than the arc described by the outside wheel. A member |00, which may be called a reach for convenience, is mounted to pivot about the axis of a pin `|02 and is connected to actuate the tie rod 98 by means of pin |04 on the tie rod cooperating with recess |06 in the end of the reach. As before, damper springs 32 may be provided to stabilize the reach.

A second member |08, which may for convenience be called a tongue, is mounted to pivot about the axis of a pin in cross member |0. As is best seen in Figure 6 the tongue |08 and the reach |60 overlap. Ahead of one of the pivot axes (that of pin |02 in the embodiment shown) there is mounted a projection such as pin ||2 in one of the pivotally mounted members (reach |00 in the embodiment shown), which extends through a transverse recess I4 in the other pivotally mounted member (tongue |08 in the embodiment shown). The upper end of pin I2 is positioned to cooperate with the longitudinal recess ||6 in a lock plate ||8. Plate ||8 is mounted for limited reciprocation relatively to tongue |08 by means of pins |20 and elongated recesses |22. Reciprocation of the plate I8 is effected by linkage comprising actuating member |24 and rod |26. Rod |26 is connected to be manipulated from the drivers seat. Actuating member |24 pivots about a pin |21 and is recessed as at |28 to cooperate with a pin |30.

A second projection such as pin |32 is provided back of the pivot axis (the axis of pin |02) on one of the pivotally mounted members (in the embodiment shown, the reach |06) and extends through a transverse recess |34 in the other pivotally mounted member (tongue |08 in the embodiment shown). Cooperable with the upper end of pin |32 is a longitudinal recess |36 in lock plate IIB.

4 Tongue |08 is connected at its forward end |33 to some portion of the tractor or towing vehicle which is to the rear of the fth wheel.

Operation In the operation of the embodiment shown in Figures l to 3, consider rst Figure l in which the trailer is shown for normal forward operation. In this figure pin 48 is free to move in the transverse portion of the T-shaped slot and consequently does not engage tongue 34. However, pin 44 on tongue 34 is in the longitudinal portion of the T-shaped recess in plate 46. With the tractor wheels turned to follow a left hand curve,

tongue 34 will pivot counterclockwise slightly about pin 36. The engagement between reach 24 and tongue 34 at pin 44 causes reach 24 to pivot clockwise about pin 26, effecting steering movement of wheels I6 in a direction to cause the trailer to follow the tractor around the curve.

Even if the train is proceeding forward down hill, the trailer cannot run up on the tractor to disengage pin 44 and engage pin 48 because the trailer and tractor are maintained in their relative positions as shown in Figure 1 by the lock mechanism 60. Elongated member 16 abuts against member 56 to maintain the positions shown.

When it is desired to back up with the train, member 16 is rotated through 90 by means of the linkage shown, whereupon, with the trailer wheel brakes set, the tractor is backed up permitting elongated member 16 to pass through the elongated recess 58, at the same time that pin 48 engages the longitudinal part of the T-shaped recess and pin 44 disengages the longitudinal portion of its cooperating T-shaped recess. Elongated member 16 of the lock mechanism is again rotated through to hold the parts in the position shown in Figure 3. If now the towing vehicle wheels are turned to the right, tongue 34 is pivoted counterclockwise about its pivot 36 and through the pin 48 also pivots reach 24 counterclockwise about its pivot 26, turning the trailer wheels in the proper direction.

For normal forward operation of the semitrailer embodiment shown in Figure 4, the lock plate occupies the position shown in this gure. If the tractor is steered to the right, tongue |08 is pivoted counterclockwise about its pin ||0 pivoting the reach |00 clockwise about its pin |02. For a better understanding of this operation see Figure 5, which shows thel parts in their forward running position. To back up with the train of Figure 4, lock plate ||8 is shifted to disengage pin |2 and engage pin |32. In that event, turning the tractor wheels to the right rotates tongue |08 clockwise. With the plate shifted, reach |00 also pivots clockwise about its pin |02 and the wheels 92 are turned in the proper direction.

It will, of course, be understood that the selector and lock plate ||8 shown in the embodiment of Figure 4 may be used in the trailer of Figure 1.

I claim:

1. A dirigible trailer comprising a frame mounted on a pair of dirigible wheels, an actuator for the wheels disposed entirely on one side of the steering axes of the wheels, a member operably engaging the actuator and mounted to pivot about a given axis on the frame, a second member mounted to pivot. about a given axis on the frame and in position to engage the rst member, and means to selectively engage the two members on either side of the aforesaid pivot axis of said iirst named member,

2`. The invention of claim 1, in which the means includes a projection on one of the members positioned to cooperate with a recess in the other member.

3. The invention of claim 1, in which the two members are relatively reciprocable, and selective engagement is accomplished by relative reciprocation.

4. The invention of claim 1, in which the lastnamed means includes a projection on one of the pivotally mounted members, and a recessed movably mounted selector on the other pivotally mounted member.

5. A dirigible trailer comprising a pair of dirigible wheels, an actuator for the Wheels disposed entirely on one side of the steering axes of the wheels, a member operably engaging the actuator and mounted to pivot about a given axis, a second member mounted to pivot about a given axis in position to engage the rst member, a projection on one of the pivotally mounted members and mounted forward of one of the pivot axes, a second projection on one of the pivotally mounted members and mounted to the rear of said pivot axis, and means to select one of the projections to eect engagement of the two pivotally mounted members.

6. The invention of claim 5, in which the lastnamed means includes a selector which is recessed and movable to cooperate with one of the projections to effect engagement of the two pivotally mounted members at the selected projection.

7. A dirigible trailer comprising a pair of dirigible Wheels, a member connected to move the wheels in unison and mounted to pivot about a given axis, a second member mounted to pivot about a given axis in position to engage the rst member, a projection on one of the pivotally mounted members, a recess on the other pivotally mounted member cooperable with the projection, a second projection on one of the pivotally mounted members, and a second recess on the Ale() other pivotally mounted member cooperable with the second projection when the first-named projection and its associated recess are disengaged.

8. The invention of claim '7, in which a projection and its cooperating recess are engaged by movement of the trailer relatively to its tractor.

9. The invention of claim 7, in which a projection and its cooperating recess are engaged by movement of the trailer relatively to its tractor, and means to lock the members in the selected engagement.

10. In a dirigible trailer of a tractor-trailer train, a pair of dirigibly mounted Wheels, a member mounted to pivot about a given axis and connected to move the wheels in unison, a second member mounted to pivot about a given axis in a position to engage the first member, a projection on one of the pivotally mounted members and mounted forward of one of the pivot axes, a second projection on one of the pivotally mounted members and mounted to the rear of said pivot axis, and means to select one of the projections to effect engagement of the two pivotally mounted members.

11. The invention of claim 10, in which the last-named means includes a selector which is recessed and movable to cooperate with one of the projections to effect engagement of the two pivotally mounted members at the selected projection.

GEORGE D. WILLET.

REFERENCES CITED The following references are of record in the 

